Hello, I just found this post while searching for solutions to make an mp3 interface for my car without building a carputer.

I am trying to make an interface utilizing the hardware I already have (ipod, various other mp3 players, pocket pc, external hard drive, flash drive (+ going to buy a clarion EQS746 for audio i/o)

Looking at the Grom devices made me think: If they can make a usb interface which allows you to control hard drives and ipods with the factory radio controls, shouldn't it be possible (and perhaps easier) to make a usb interface which allows you to control a hard drive or ipod with a pocket pc or other similar electronic device?